Women told to keep taking Tamoxifen

Cancer Research UK has warned women who do not take the drug Tamoxifen for the full five year period run the risk of their breast cancer coming back.

The charity said that around 50% of women who took the drug stopped the course early but by doing so they reduced their chances of survival.

Statistics have shown that six women or less in every hundred will have a recurrence of breast cancer if they complete the full course of the drug.

The drug is usually prescribed to women who have oestrogen-receptive breast cancer. Tamoxifen can block the oestrogen from feeding the growth of tumours.

However, Tamoxifen can have side effects such as hot flushes and some women may believe they do not need to keep taking it for the full course.

Of the 3,500 patients in the study, cancer returned to around 40% of the women who took Tamoxifen for five years, in comparison to 46% in women who took it for two years.

Dr Allan Hackshaw, lead author of the research published in the Journal of Clinical Oncology, said: "Our study provides conclusive evidence that taking tamoxifen for five years offers women the best chance of surviving breast cancer."

"Women diagnosed with early stage breast cancer who are prescribed Tamoxifen are recommended to take the drug for five years, but we know that many stop after two or three. Worryingly our results suggest that by doing this, they could increase their risk of cancer coming back."